Topic

While it's winter I decided to renew the cylinder head gasket, timing belt etc. I've had the car six years and did it as a precaution. I'm glad I did, the timing belt was a bit worn, cylinder head gasket was fine, but head was dirty with a couple of burned valves and seats.
Anyway, while the head is off I've cleaned up the ports and chambers, but lookIng at the head it reminded me in some was of my old A series mini. The inlet valves especially are shrouded by the sides of the combustion chamber (see photo).
From measurement there is around 3mm from the edge of the chamber to the cylinder wall. So I was thinking some metal could be removed near the valve to give better flow at low valve lifts. But I've never seen this mod in any of the things I've read about improving k series engines. Is this because there's an obvious problem? Any thoughts on this would be welcome

Brings back memories A series with a 12G295 head casting and me with a selection of grindstones, the car ran fine and strong afterwards so I'll call it a success. This mainly entailed gas flowing the exhaust, the inlets not so much as some turbulence assisted petrol/air mixing (or so I was taught). Great care was also taken to ensure manifold to head joints lined up with no step to impede flow which included filing gaskets to fit, perhaps another area to look at? Would I attempt it now with my TF no I haven't got the bottle and A series heads were 2 a penny if you cocked up.
Looking at the (very good) photo I do wonder if the small amount you could remove would make much difference, are there any photos of works/racing heads to compare? Also reaching back into the mists of time I think if space was available bigger valves was the option of choice then something MG seem to have exploited to it's fullest.
Regardless of my comments if you want to have a go the very best of luck to you :clap

12g295. Now that was a good head. Built an 1100 Morris Minor with one of those and sundry other bits. The lady I built it for had a tired 948 in it and it was flat out at 50 so 70 in third was a great improvement. Things were easier then. Engines were not made to be fuel efficient so the power output was pretty woeful. A well tweaked 1100 made about 63-65 BHP. My one litre Ford makes double, uses half the fuel and will last twice as long. The VVC engine makes an easy 160 with the right air filter, exhaust and throttle body. The time and cost of head mods is pretty disproportionate for the gain. Lotus spent a lot getting 190 out of it
Match the ports to the manifolds and leave the rest alone unless you have a flow bench. If you want to go faster, I reckon louvring the bonnet to reduce front end lift would reduce drag a fair bit and spend the dosh on dampers and tyres instead ' cos grip makes speed more easily than horsepower .

Amazing how many people cut their teeth messing about with Mini's, and still know what a 12G295 head is. I could never afford one so modified my 998cc head as per triple C recommendations. Matched the manifolds etc, and had a quick little motor that could keep up with an XR 2I. I agree car engines are much better and efficient these days, but they are mass produced, so I think the rules of marginal gains applies. I've read Roger Parkers book and articles and followed his ideas generally but as said when I looked at the head I thought it could be improved slightly. The must be enough metal as larger vvc valves can be retrofitted, I then re- read my old copy of 'theory and practice of cylinder head modications' and thought yep, let's have a go. Result is very subtle change, which will probably have little effect, but hopefully will improve mid range torque, we'll see (fingers crossed). I agree about comments re suspension etc, and have spent the last few winters working on that. My F now rides and handles better, so roll on the summer, and hope j can get all the right bits back in the right order.